Bookmarks
NL Net Foundation
theMage:
The NLNet foundation is a ditch non-profit organization dedicated to increase privacy in the internet and hardening it.
piperka
Comic's Collector:
A web comic bookmarking and tracking service that's been around since 2005.
The leaderboard ad is shown on both the mobile and desktop versions of the site (if the browser window isn't too narrow for it). The skyscraper ad is only used on the desktop site which most of my users use.